Thermally actuated timing device



March 29, 1955 My 2,705,048

- Tl-iERHALLY ACTUATED TIMING DEVICE Filed Nov. 15. 1952 2 Sheets-Sheet l INVEN TOR. G45 TON M4 5) March 29, 1955 Filed Nov. 15, 1952 G. WILEY THERMALLY ACTUATED TIMING DEVICE 2 Sheets- Sheet 2 INVENTOR. GA: ro/v MLEY United States Patent THERMALLY ACTUATED TIMING DEVICE Gaston Wiley, Mount Fern, Dover, N, I.

Application November 15, 1952, Serial No. 320,718

12 Claims. (Cl. 161-15) The present invention relates to a novel thermally actuated timing device.

Objects and advantages of the invention Wlll be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings:

Figure l is an exploded fragmentary top plan view of a typical and illustrative embodiment of the present invention; 7

Figure 2 is a fragmentary perspective view of the escapement mechanism shown in Figure 1;

Figure 3 is a sectional view taken on the lines 3-3 of Figure 1; and

Figure 4 is a sectional view taken on the lines 4-4 of Figure l.

The present invention has for its object the provision of a novel timing device which is normally at rest and is adapted to be set in operation upon apredetermined change in temperature. A further object of the invention is a provision of a timing device for controlling the operation of other mechanism and which begins its timing function only when a temperature change of a predetermined amount has taken place. A further object is the provision of a heat-responsive system which has a delayed action and performs its function only after a period of delay at a given temperature. The invention further provides a thermally actuated timing mechanism which can be adjusted for various periods of delay, and can be set to operate upon a predetermined increase or decrease in the measured temperature.

The present invention provides a control mechanism which may be applied in many ditIerent'ways,-for instance to actuate signal mechanism after a predetermined rise in temperature has been measured for a predetermined period, to arm a land mine, enabling the mine to be buried at a cool temperature, for instance at night, and causing it to be armed only after the ground has been warmed by the sun, or alternatively, it may serve as a signal of freezing danger and control the signal only when the temperature has dropped to freezing or below for a predetermined period.

The control mechanism of the present invention preferably comprises broadly a thermally responsive member, an escapement normally held against running but released for running by movement of the thermally responsive member, power means for driving the gearing under control of the escapement, means for changing the rate of running of the escapement and gearing, means for insuring starting of the escapement when the predetermined temperature change has taken place, together with switch or other signal control means to be actuated by the powered gearing upon completion of a predetermined time of running.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

2,705,048 Patented Mar. 29, 1955 Referring now in detail to the present preferred and llustrative embod ment of the present invention as shown in the accompanying drawings, there is provided a train of powered gearing comprising a main spring 10 which may be wound by a manually rotated pinion 12 engaging the crown teeth 11 on spring barrel 14 having a hub to wh ch the inner end of the main spring 10 is made fast, while the outer end is fixed to the stationary post 16. Spring barrel 14 is also formed with peripheral teeth 18 and pinion teeth 20, the pinion teeth serving to drive a control d sc 22 in either direction, while the teeth 18 mesh with idler 24 to drive a pawl-mounting pinion 26 mounted coaxially with the fourth wheel 28 carrying ratchet 30 in turn driven from the pawl 32. As pinion 12 is turned 1n one direction to wind the spring 10, wheels 14, 20, 22, 24 and 26 are turned in one direction, while running of the mechanism causes them to turn in the opposite direction.

Fourth wheel 28 drives pinion 34 fixed to the escapement wheel 36 so that the escapement wheel tends to turn in a clockwise direction.

The escapement is illustratively a modified form of balance wheel lever escapement and comprises a fifteentoothed escapement wheel assembly 40 working with a pivoted pallet assembly 42 having the receiving and discharging ewels 44, 46 to work with the escapement teeth 48 in the usual manner. Pallet assembly 42 may oscillate between the two banking pins 50' as the pallet fork 52 and guard pin 54 work with the roller pin 56 and guard pin notch 58 forming the double roller of the balanced wheel assembly. The inertia wheel 60 has its staff 62 pivoted in jewels or other bearings in the balance bridge 63 and in the bottom plate (not shown) and 18 also connected with an oscillator arresting rod 64 which projects at a slight angle, but generally radially oi the inertia staff.

Coaxial with the inertia staff 62 is pivotally mounted a regulator 66 which can be moved for adjustment but is normally held frictionally about the cap top end member 68. At its outer end, regulator arm 66 is provided with a regulator key 70 in which is guided a long, flat, thin detent spring 72 having adjustably mounted thereon two detents or drum studs 74, one at either side of the arrestor rod 64, the detents being slotted and frictionally held on the spring 72 so as to allow a slight oscillation of the arrestor rod 64, which may be just sufiicient for full actuation of the pallet arm 42 by the roller pin 56. or may be much greater if a slower operation is desired. The action of the arrestor rod 64 in hitting one of the detents 74 and the resiliency of the spring 72 causes the arrestor arm 64 and inertia wheel 60 to rebound, thereby giving a vigorous'oscillation to the inertia wheel until the oscillation is reversed by engagement of the rod 64 with the other detent or drum 74.

Spring 72 is free to slide in the regulator key 70 and carries with it the detents or drums 74. In their normal position, one drum 74 or the other holds the arrestor rod 64, inertia wheel 60 and roller pin 56 to one side of the center of their normal oscillation and causes the roller pin 56 to hold the pallet so that the escapement is locked, but by moving the spring 72 lengthwise in one direction or the other until the'arrestor rod 64 may oscillate, oscillation of the pallet assembly 42 is allowed and the escapement 40 has its intermittent rotation.

The anchored end of spring 72 it made fast to the thermally moved wheel 80 by means of a pair of holding screws 82, so that rotation of the wheel 80 causes the spring 72 to be moved back and forth through the regulator key 70 to'p'osition the drums 74 or detents to block oscillation of the arm 64 or, alternatively, to allow it to vibrate rapidly. Wheel 80 is urged to rotate in a clockwise direction by means of a spirally coiled spring 84 which has one end secured to the shaft 86 of the wheel 80, while its other end is secured to the regulator 66 by means of stud 88 in which it is anchored by stud pin 90.

Wheel 80 is adapted to be moved in response to changes in the ambient temperature so that the position of the drum detents 74 is accordingly changed. As embodied, a pinion 92 is fast on the shaft 86 and meshes with an idler gear 94 and is reversibly driven from a gear seg- "ice 96 mounted on a bimetal strip 98, arcuately curved and anchored to a thermally conductive member 100 which receivesheat from the exterior of the control instrument and attains a temperature correspond ng to the ambient temperature by conduction and radiation. The bimetal member 98 is so constructed, as illustratively embodied, that on being cooled it moves to the left, and on being warmed, as when the sun warms the earth m which the instrument is buried, moves to the right, thereby moving the wheel 80 in the same angular direction.

Thus, assuming that the instrument is adjusted so that it is normally inoperative and will remain inoperative until the bimetal element has attained a temperature of about 30 F., the instrument may be buried in a freezing compartment which normally maintains a temperature of about F. but which may become warmer if there is a power failure or if the compartment is left open for too long a duration. Under such conditions, the oscil-.

lator arrestor rod 64 is held against movement against one of the drums 74, thereby holding the escapement wheel 40 against release. A short time after the ambient temperature has reached 30 F. bimetal element 98 contracts sufliciently to move the wheel 80 and the spring carried drums 74 so that the rod 64 is free to vibrate under the influence and impulsion of the main spring 10, and thereby the instrument is set in operation so that a predetermined time after the critical temperature has been reached, the desired signal or indicating operation takes place. Spring 84 serves to take up the backlash in the thermally actuated portion of the system and also serves to move the wheel 80 to its releasing position under control of the bimetal element 98.

As escapement 40 moves under the force of main spring 10, gear 22 moves in a clockwise direction, the rapidity of the movement of the gear 22 being dependent upon the gear ratio existing between the escapement 40 and the gear 22. Any desired type of mechanism may be operated fromthe main spring 10 under control of the escapement 40, as it runs when the temperature conditions are suitable, but illustratively, gear 22 carries a pin 106 on its face which is adapted to engage with a fixed stop member 108 which prevents overwinding of the main spring 10 as the instrument is initially wound, and as the instrument is set in operation by the prevailing temperature conditions, it serves to actuate signal or actuating means which are illustratively shown as comprising an electric switch 110 adapted to be closed when the full period of operation has been achieved. With such an embodiment, the switch 110 may cause an electrically actuated hell or other signal to be energized when the full period of time at a given temperature has been reached, or the switch may merely serve to condition an additional switch, notshown, so that closure of the second switch will thereby cause the desired operation to take place. Thus, the switch 110 may arm a land mine and thereby render it sensitive so that it will be responsive to pressure or other triggering force.

In the illustrative embodiment, the operative temperature range may be adjusted by the position of the drum detents 74 on the spring member 72, the extent of the temperature range may be adjusted by the spacing of the drum detents from each other, which also adjusts the rate of oscillation of the inertia wheel 60, while the rate of oscillation of the inertia wheel may be adjusted apart from other factors by positioning the spring 72 in the regulating key 70 so as to vary the frequency of the spring. The period of delayed operation is obviously governed by the gear ratio existing between the escapement wheel 40 and the gear 20, while it may also be controlled by the extent of winding as determined by the number of turns given the pinion 12 as the instrument is placed in operation, although it is-shown'in Figure l as being fully wound.

What is claimed is:

l. A thermally actuated timing device, including in mally responsive means for moving said holding meansfrom its holding position to permit running of the oscil latory member and a control member moved in accordance with the running of the escapement.

2. A thermally actuated timing device as claimed in claim 1 having a one-way clutch connected between the escapement and control member to enable the control member to be turned in one direction under control of the escapement and to be freely turned in the other direction without control.

3. A thermally actuated timing device including in combination a main spring driving an escapement wheel, a pallet controlling the running of the escapement, an oscillatory lever controlling the pallet, spaced stops engaging the oscillating lever, thermally actuated means for shifting the stops to permit oscillation of the lever and running of the escapement wheel, and a control member driven from the main spring in accordance with the running of the escapement.

4. A thermally actuated timing device as claimed in claim 3 in which the escapement wheel, and pallet are connected to an inertia wheel to form a lever escapement, and the oscillatory lever is mounted on the inertia wheel.

5. A thermally actuated timing device as claimed in claim 3 in which the spaced stops are variably positioned on a long thin spring moved across the lever by the thermally actuated means.

6. A thermally actuated timing device as claimed in claim 5 in which the escapement wheel and pallet are connected to an inertia wheel to form a lever escapement, and the oscillatory lever is mounted on the inertia wheel.

7. A thermally actuated timing device as claimed in claim 6 in which the thermally actuated means comprises a-bimetal arcuate member carrying a toothed portion engaging gear means for actuating the stop-carrying spring.

8 A thermally actuated timing device as claimed in claim 3 in which the escapement wheelpand pallet are connected to an inertia wheel to form a lever escapement, the lever is mounted on the inertia wheel and the spaced stops are carried by a long, thin spring extending across the lever and moved by the thermally actuated means.

9. A thermally actuated timing device as claimed in claim 8 in which a guide key is provided for the stopcarrying spring and may be variably positioned with respect to the oscillatory lever.

10. A thermally actuated timing device including in combination a bimetal member, a toothed member moved thereby, a gear meshing with the toothed member, a pair of spaced stops mounted on a spring moved by the gear, an escapement having an oscillatory member normally held against movement by the stops and released on a temperature change from a normal temperature, and a control member progressively moved towards an actuating position under control of the escapement.

11 A thermally actuated timing device as claimed in claim 10 in which the bimetal member is mounted on a heat-conductive metal support.

Preferably the entire instrument is mounted in a closed case so that it may be buried or isolated from external conditions, other than temperature.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying clairns without departing from the princtples of the invention and without sacrificing its chief advantages.

12. A thermally actuated timing device as .claimed in claim 10 having escapement engaging stops variably positioned on a thin, long spring extending across the ever.

References Cited in the file of this patent 

